[Prediction of falls with performance on Timed "Up-and-Go" and one-leg-balance tests and additional cognitive tasks].

Objective: This study aimed to determine whether ordinary clinical performance on the timed "up-and-go" and one-leg-balance tests varied with additional cognitive tasks and the predictive value of this combination for future falls.

Methodology: The sample comprised 95 women with osteoporosis who lived independently in the community and were older than 70 years (mean 73.4+/-1.

Postural control during quiet standing following cervical muscular fatigue: effects of changes in sensory inputs.

The purpose of the present experiment was to investigate the effects of cervical muscular fatigue on postural control during quiet standing under different conditions of reliability and/or availability of somatosensory inputs from the plantar soles and the ankles and visual information. To this aim, 14 young healthy adults were asked to sway as little as possible in three sensory conditions (No vision, No vision-Foam support and Vision) executed in two conditions of No fatigue and Fatigue of the scapula elevator muscles. Centre of foot pressure (CoP) displacements were recorded using a force platform.

Effects of head extension on undisturbed upright stance control in humans.

The purpose of the present experiment was to investigate whether and how the head extended posture, commonly encountered in many routine activities, affects undisturbed upright stance control mechanisms in humans. Sixteen young healthy adults stood feet together, with their eyes closed and were asked to sway as little as possible in two Neutral and Extended head conditions. Centre of pressure (CP) displacements, recorded using a force platform, were used to compute the motions of the vertical projection of the centre of gravity (CG(v)) and those of the difference CP - CG(v).

Mirror versus stationary cross feedback in controlling the center of foot pressure displacement in quiet standing in elderly subjects.

Objective: To investigate the effect of mirror feedback on postural control during quiet standing in elderly adults.

Design: Before and after intervention trials.

Setting: Pneumology center in France.

Attentional demand for regulating postural sway: the effect of expertise in gymnastics.

A dual-task paradigm was used to investigate whether the expertise in motor skills requiring a fine postural control can modify the attentional demand necessary for regulating postural sway. Seven expert gymnasts and seven experts in other non-gymnastic sports were asked to respond as rapidly as possible to an unpredictable auditory stimulus while maintaining stable seated and in three upright postures of increasing difficulty: bipedal, unipedal, and unipedal on an unstable support (i.e.

Effect of light finger touch on postural sway after lower-limb muscular fatigue.

Objective: To investigate whether a light finger touch can compensate for the increased postural sway induced by lower-limb muscular fatigue.

Design: Before-after trials.

Setting: General community.

Attentional demands and postural sway: the effect of the calf muscles fatigue.

Purpose: The purpose of the present experiment was to investigate whether the calf muscle fatigue affects postural sway in bipedal stance and requires additional attentional demands.

Methods: Nine healthy university students had to respond as rapidly as possible to an unpredictable auditory stimulus while maintaining stable seated and upright postures with their eyes closed in two conditions of no-fatigue and fatigue of the calf muscles. Center of foot pressure (COP) displacements were recorded using a force platform.

Postural sway under muscle vibration and muscle fatigue in humans.

Separate studies have demonstrated that vibration and fatigue of ankle muscles alter postural control. The purpose of the present experiment was to investigate the effect of ankle muscle vibration on the regulation of postural sway in bipedal stance following ankle muscle fatigue. Center of foot pressure displacements were recorded using a force platform.

Veering in human locomotion: modulatory effect of attention.

Without visual information, human subjects are not able to maintain displacement in a straight line. This tendency to depart from linearity during locomotion is called veering. The purpose of the present experiment was to investigate the extent to which attention could modulate navigation in the absence of visual information.

Effects of lower limbs muscular fatigue on anticipatory postural adjustments during arm motions in humans.

Background: The purpose of the present experiment was to examine the effects of lower limbs muscular fatigue on the anticipatory postural adjustments during a voluntary arm raising movement.

Methods: Eight adult males (mean age 29+/-6 years) voluntarily participated to the experiment. Subjects' task consisted in performing an unilateral ante-flexion of the right arm over 90 deg, holding a 500 g weight, once having stabilized their upright posture.

The effect of expertise in gymnastics on proprioceptive sensory integration in human subjects.

The ability of experts in motor skills requiring a fine postural control to keep a stable upright posture while facing the task of reinserting proprioceptive information was investigated. Seven expert gymnasts and seven experts in other non-gymnastics sports were asked to stand as immobile as possible in two conditions of vision and no-vision. Within a trial, ankle proprioceptive input was modified by means of tendon vibration of both antagonistic ankle muscles.

Can vision compensate for a lower limbs muscular fatigue for controlling posture in humans?

The purpose of the present experiment was to investigate the effect of vision on postural control following a lower limbs muscular fatigue. Ten adult males were asked to maintain a single leg upright posture as immobile as possible in two conditions of no-fatigue and fatigue of the calf muscles. This muscles fatigue was achieved by standing on the toes until exhaustion.

The effect of expertise in gymnastics on postural control.

The goal of this paper was (1) to investigate if gymnasts have a more stable standing posture than experts in other sports, and (2) to determine how much gymnasts are affected by the removal of vision in different postural tasks. Six expert gymnasts and six experts in other non-gymnastic sports were asked to maintain balance in three standing postures of increasing difficulty: bipedal, unipedal, and unipedal + unstable support (i.e.

Effects of a reaction time task on postural control in humans.

The purpose of the present experiments was to investigate the effects of a reaction time (RT) task on postural control, during and following the execution. Three different RT tasks consisting in verbal responses to visual and auditory stimuli were supposed to require different demands on cognitive resources. There was also a control condition in which no concurrent task was required.